The Mycosynth Gardens is a rare Land — Sphere card from Phyrexia: All Will Be One Promos (PONE), collector number 256s. Current market price: — (foil $6.49), TCGplayer market prices via Scryfall.
{T}: Add {C}. {1}, {T}: Add one mana of any color. {X}, {T}: This land becomes a copy of target nontoken artifact you control with mana value X.